11.     what are the two gases that escaped earth's atmosphere during early formation?  
            a.  hydrogen and helium    b.  helium and nitrogen    c.  hydrogen and nitrogen    d.  helium and oxygen 

A. Hydrogen and helium

Explanation:

Hydrogen and helium escaped the earth's early atmosphere. A cloud of gases surrounded the early earth that primarily had no magnetic field and gravity to trap some of the gases.

This was why these light weight gases were able to escape the early earth's atmosphere and we don't have them today.

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.